How To Dynamically Select A Method Call?

I have a code similar to this: if command == 'print': foo_obj.print() if command == 'install': foo_obj.install() if command == 'remove': foo_obj.remove() command

Solution 1:

Use getattr and call its result:

getattr(foo_obj, command)()

Read that as:

method= getattr(foo_obj, command)
method()

But of course, be careful when taking the command string from user input. You'd better check whether the command is allowed with something like

commandin {'print', 'install', 'remove'}

Solution 2:

self.command_table = {"print":self.print, "install":self.install, "remove":self.remove}

def function(self, command):
    self.command_table[command]()

Solution 3:

The core function may be as:

fn = getattr(foo_obj, str_command, None)
ifcallable(fn):
    fn()

Of course, you should allow only certain methods:

str_command = ...

#Double-check: only allowed methods and foo_obj must have it!
allowed_commands = ['print', 'install', 'remove']
assert str_command in allowed_commands, "Command '%s' is not allowed"%str_command

fn = getattr(foo_obj, str_command, None)
assertcallable(fn), "Command '%s' is invalid"%str_command

#Ok, call it!
fn()    

Solution 4:

Create a dict mapping the commands to the method call:

commands = {"print": foo_obj.print, "install": foo_obj.install}
commands[command]()

Solution 5:

functions = {"print": foo_obj.print,
             "install": foo_obj.install,
             "remove": foo_obj.remove}
functions[command]()